Mercurial > ~darius > hgwebdir.cgi > stm32temp
changeset 14:891841f5f785
Fix delay() to be accurate as measured on the cro.
| author | Daniel O'Connor <darius@dons.net.au> |
|---|---|
| date | Wed, 14 Nov 2012 12:24:21 +1030 |
| parents | 96c345d304af |
| children | b12881051261 |
| files | delay.c delay.h |
| diffstat | 2 files changed, 77 insertions(+), 8 deletions(-) [+] |
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--- a/delay.c Wed Feb 08 10:37:22 2012 +1030 +++ b/delay.c Wed Nov 14 12:24:21 2012 +1030 @@ -2,13 +2,82 @@ #include "stm32f10x.h" #include "delay.h" -/* This is a bit rough and ready */ +/* Sleep for nCount usec + * TDS1012 on 2.5usec/div shows... + * 30usec = 29.60usec + * 60usec = 59.20usec + * + * XXX: not sure disable IRQ stuff is working as I see occasional (small) extra delays + */ void -delay(__IO uint32_t nCount) { - __IO uint32_t i; - - for(; nCount != 0; nCount--) - for (i = 0; i < 3900; i++) - ; +delay(uint32_t nCount) { + __disable_irq(); + for(; nCount != 0; nCount--) { +#ifdef SYSCLK_FREQ_72MHz + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); + __asm__("nop"); +#else +#error Unknown clock frequency +#endif + } + __enable_irq(); }